Process of separating the mixtures of isomeric 1.4. 5. 8-naphthoylene-diarylimidazoles and new dyestuff obtained thereby



Patented Mar. 27, 1934 TATES PATENT OFFICE 1,952,661 rRocEss 0F SEPARATING THE MIXTURES OF ISOMER-IC 1.4.5.

ARYLIMIDAZOLES S-NAPHTHOYLENE -DI- AND NEW DYE STUFF dorf, Frankfort 1 on the Main-Hochst, Germany, assignors to General Aniline Works, Inc.-, New York, N. Y., a corporation of Delaware No Drawing. Application June 30, 1931, Serial "No. 548,022. in Germany August 12, 1930 8 Claims.

The present invention relates to a process of separating the mixtures of isomeric 1.4.5.8- naphthoylene-diarylimidazoles obtainable by condensing a 1.4.5.8-naphthalenetetra-carboXylic acid compound withan ortho-diamine compound of the benzene series into their two components and to new dyestuffs obtained thereby.

We have found that the separation of the dyestuff mixtures obtainable by condensing a 1.4.5.8- naphthalenetetra-carboxylic acid compound with an ortho-diamine compound of the benzene series into their components can be eiiected with a good yield by converting the said isomeric dyestuffs, in the presence of a suitable organic diluent, for instance, a solvent or a suspending agent, by means of organic acids of the formula RSOzOl-I wherein R is a member of the benzene and naphthalene series, such as, for instance, paratoluene-sulfonic acid, naphthalene-sulfonio acids, alkyl naphthalene-sulfonic acids, into the corresponding salts and separating the salts from each other by taking advantage of their different solubility. As solvents or suspending agents there may be used, for instance, chlorobenzene, nitrobenzene, glacial acetic acid or the like.

Among the products obtainable according to the present invention those are to be considered as new which have the probable general formula:

wherein R represents the bivalent radical and'one X and Y mean hydrogen and the other X and Y mean --CO.CH3 or -CeH5, X1 being identical with Y1, and X2 with Y2.

The new products dissolve in concentrated suliuric acid to a brownish-yellow to red solutionand dye the vegetable fiber from the vat yellowish brown to violetish brown tints of good fastness Patent 1,588,451 are boiled together with-1O parts of para-toluene-sulfonic acid and about 160 parts of glacial acetic acid, the solid product is filtered by suction and subsequently washed with glacial acetic acid. From the residue on the filter there is obtained the para-toluene-sulionate of the orange dyestuif of the following probable composition:

It is a yellowish brown product whichis sparingly soluble in many organic solvents, such-as chloro benzene, nitrobenzene, glacial acetic acid or the like. The product is washedwith glacial acetic acid and then decomposed by introducing it into water; it is thenfiltered'by suction and'washed until neutral. The dyestuff is obtained in the form of an orange powder. It dissolves in monohydrate to a brownish solution and dyes cotton from an olive vat very brilliant orange tints of excellent fastness properties.

In the filtrate obtained there is contained the para-toluene-sulfonate of the bluish red dyestufi which corresponds with the following probable composition:

F I S 02.0711

It is decomposed into the dyestuff by means of water; the dyestuif is filtered by suction, washed until neutral and dried. It dissolves in concentrated sulfuric acid to a red solution and dyes cotton from an olive vat bluish red tints of very good fastness properties.

Instead of the free para-toluene-sulfonic acid there may be used a salt thereof,for instance, the sodium salt, with the addition of the quantity of sulfuric acid monohydrate required for liberating the acid.

(2) 10 parts of the dyestufi used as parent material in Example 1 are suspended in about 225 parts of chlorobenzene and 10 parts of free paratoluene-sulfonic acid are added thereto. The mixture is heated for some time to boiling during which operation the para-toluene-sulfonate of the bluish red dyestuff described in Example 1 dissolves and the corresponding salt of the orange dyestuif is precipitated. The hot product is filtered by suction, the residue is boiled again with chlorobenzene and then filtered by suction. The adhering chlorobenzene can be removed by washing with alcohol or by steam distillation. The product is further treated as described in Example 1.

(3) 10 parts of the dyestuff used as parent material in the preceding examples are boiled for a short time in about 120 parts of nitrobenzene and 7-8 parts of a free alkyl-naphthalene-sulfonic acid. After the product has been allowed to cool, the sparingly soluble alkyl-naphthalene-sulfonate of the orange dyestuif is filtered by suction and worked up as described in Example 1.

By using a naphthalene-sulfonic acid instead of the above-named acids, the dyestufis are likewise easily separated with a good yield.

(4) 10 parts of the dyestufi obtainable by condensing 1.45.8-naphthalene-tetra-carboxylic acid with l-ethoxy-l.Z-diaminobenzene according to U. S. Patent 1,588,451 are boiled with 15 parts of para-toluene-sulfonic acid and about 160 parts of glacial acetic acid; the cold product is filtered by suction and subsequently washed with glacial acetic acid. The residue on the filter consists of the para-toluene-sulfonate of a brownish yellow dyestuff and corresponds with the following probable formula:

1 2 H l/ NE/N\ 0 0sC1H1 H C CO C1H10aS 2 1 wherein the group OC2H5 stands in 4- or 5- position.

The light brown product very sparingly dissolves in most of the organic solvents. The paratoluene-sulfonate is decomposed with water, and the dyestuff thus obtained is filtered by suction and washed until neutral. The dyestuif dyes cotton from a reddish green dichroic vat green tints 195 which, when the material is exposed to the air, change to brownish-red tints.

In the filtrate obtained as described above there is contained the para-toluene-sulfonate of a brownish violet dyestufi which corresponds with the following probable composition:

O|C2H5 5 4 PM 6 y \SO: C1H1 or. t H

\O. C2H5 wherein the O.C2H5 group stands in 4- or 5-position.

The product is decomposed with water into the toluene-sulfonic acid and the dyestuff. When the dyestuff is dried, it is a brown powder dyeing cotton from a reddish green dichroic vat violettinged dark brown tints.

(5) 10 parts of the dyestufi obtainable from 1.4.5.8-naphthalene-tetra-carboxylic acid and 4- chloro-l.Z-diamino-benzene yield, if treated as described in Example 1, a sparingly soluble orange toluene-sulfonate. After the decomposition with water, the product yield a brownish yellow dye- 14-5 stuff which dyes cotton from a reddish green clear brownish red tints.

From the filtrate a dyestufi" is precipitated by water, which dyes cotton reddish brown tints.

(6) By carrying out the treatment described in the preceding examples with the dyestuff which is obtainable from 1.4.5.8-naphthalene-tetra-carboxylic acid and 3.4-diaminodiphenyl and which correspond with the following probable constituwherein R represents the group and the group stands in 4- or B-position in the presence of glacial acetic acid there is obtained a dyestufi from the sparingly soluble para-toluene-sulfonate, which has a reddish-brown color, dissolves in concentrated sulfuric acid to cherryred solution and dyes cotton from a green vat brownish-red tints. The soluble salt contained in the filtrate yields after its decomposition a violetish brown dyestuif which dissolves in concentrated sulfuric acid to a red solution and dyes cotton from a yellowish green vat violet tinged brown shades. The melting points of the dyestuffs are above 300 C.

(7) By a similar treatment of the dyestuff obtainable from 1.4.5.8-naphthalene-tetra-carboxylic acid and 3.4-diamino-acetophenone and corresponding with the following probable formula:

I 514 e 2 N N wherein R represents the group and the group COCHs stands in 4- or 5-position in the presence of chlorobenzene there is obtained from the more sparingly soluble toluenesulfonate a yellowish-brown product which probably corresponds with the transconfiguration and from the other sulfonate a reddish-brown dyestufi which probably corresponds with the cisconfiguration. Both dyestuffs dissolve in concentrated sulfuric acid to brownish-yellow solutions and dye cotton from an olive green vat.

4-chloro-1.2-diaminobenzene, 3.4 diaminodiphenyl and 3.4-diaminoacetophenone referred to in the above examples may be prepared from 4- chloro-aniline, 4-amino-diphenyl and 4-aminoacetophenone respectively by conversion into the corresponding acetyl compound, subsequent nitration of the acetyl compound, saponifcation of the nitrated product to produce the corresponding ortho-nitro-amino-derivative and reduction of the latter to the ortho-diamine.

We claim:

1. The process which comprises treating a mixture of isomeric l.4.5.8-naphthoylene-diarylimidazoles, obtainable by condensing a 1.4.5.8- naphthalene-tetra-carboxylic acid compound with an ortho-diamine compound of the benzene series, with an organic acid of the formula R.SO2OH wherein R is a member of the benzene and naphthalene series in the presence of an inert organic diluent and separating the mixture of isomeric salts thus obtained into its components by taking advantage of their different solubility.

2. The process which comprises treating a mix ture of isomeric 1.4.5.8-naphthoylene-diarylimidazoles, obtainable by condensing 1.4.5.8-naphthalene-tetra-carboxylic acid with 1.2-diaminobenzene, with para-toluene-sulfonic acid in the presence of chlorobenzene and separating the mixture of isomeric salts thus obtained into its components by taking advantage of their different solubility.

3. The process which comprises treating a mixture of isomeric 1.45.S-naphthoylene-diarylimidazoles, obtainable by condensing 1.4.5.8- naphthalene-tetra-carboxylic acid with 3.4-diamino-diphenyl, with para-toluene-sulfonic acid in the presence of glacial acetic acid and separating the mixture of isomeric salts thus obtained into its components by taking advantage 125 of their different solubility.

4. The process which comprises treating a mixture of isomeric 1A.5.S-naphthoylene-diarylimidazoles, obtainable by condensing 1.4.5.8- naphthalene-tetra-carboxylic acid with 3.4-di- 1'30 amino-acetophenone, with para-toluene-sulfonic acid in the presence of chlorobenzene and separating the mixture of isomeric salts thus obtained into its components by taking advantage of their different solubility. 35

5. The compounds of the general probable formula:

/0 I no N R X2 \0 .l

H wherein R represents the bivalent radical C%N Y1 N Y: --o

the tWO g1 p standing in 4- or 5-position, said product having a red-brown color, dissolving in concentrated sulfuric acid to a cherry red solution and dyeing cotton from a green vat reddish-brown tints.

'1. The compound of the probable formula:

the two groups CO.CI-I3 standing in 4- or 5-position, said product being a brown powder, dissolving in concentrated sulfuric acid to a brownishyellow solution, dyeing the vegetable fiber from an olive vat reddish-brown tints and melting at above 300 C.

8. The compound of the probable formula:

4 2 CHaOC--5 the two groups -CO.CH3 standing in 4- or 5- position, said product being a brown powder, dyeing the vegetable fiber from an olive vat very clear yellowish-brown tints.

WILHELM ECKERT. ERNST FISCHER. OTTO BRAUNSDORF. 

